This study examines the effects of the reduction of insulin concentrations using the medication, metformin, on both spontaneous ovulation and on ovulation in response to the medication, clomiphene citrate. We know that many women with the polycystic ovary syndrome (PCOS) do not ovulate spontaneously and often do not respond well to a drug commonly used to induce ovulation known as clomiphene citrate (Clomid). We also know that many women with polycystic ovary syndrome have elevated insulin concentrations in their blood. If insulin levels are reduced with diet and exercise, women with PCOS often begin to ovulate spontaneously. However, many women with PCOS find it very difficult to lose enough weight and/or exercise enough to lower their insulin levels. Metformin is a drug that has been shown to lower insulin levels and, therefore, may prove to be useful in treating women with the polycystic ovary syndrome who desire fertility. We hope to learn whether obese women with the polycystic ovary syndrome will have an increased rate of spontaneous ovulation or a higher rate of clomiphene-stimulated ovulation when serum insulin levels are reduced.